The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Each day, the sun provides 10,000 times the amount of energy utilized by the human race. In a single day, it provides more energy than our current population would consume in 27 years. In North America alone, it is believed that close to two trillion dollars is spent annually on energy, much of which is designated towards non-renewable, carbon-based sources, such as oil, coal, and other fossil fuels. When energy consumption for the average U.S. household is approximately 65-80% thermal and approximately 20-35% electrical, it makes sense to derive a means of satisfying both of these requirements through renewable sources.
There have been many advances in the past few decades toward the capture of renewable energy resources, such as water turbines (which convert the kinetic energy of moving water into electricity), wind generators (which convert the energy of the wind into electrical energy), geothermal heating (which utilizes the stability of the subterraneous temperature to provide thermal energy), and solar cells (which allow the capture and conversion of solar energy into electrical energy).
Solar panels are manufactured by joining individual solar cells to form a strip or series of individual cells which are mounted in a tray having a substantially flat mounting surface. The cells are adhered to the tray and are surrounded or encapsulated within a transparent material in such a manner that light entering the solar panel will pass substantially unobstructed through the transparent encapsulant for the cells and will impinge upon exposed surfaces of the individual solar energy cells. Typically, a solar panel is formed from at least one solar energy cell in the form of a thin, 3-inch diameter wafer that has one of its two planar surfaces adhered to the flat base of the tray that comprises the base element of the solar panel and the other planar surface of the cell directed toward the open top of the tray and in position to receive light impinging thereupon. The transparent material is usually selected from those that will not only provide minimal obstruction to the passage of light through the encapsulating material to the exposed planar surface of the cell, but which will also have optimal weathering characteristics to protect the encapsulated cells from ambient conditions. An example of this can be found in U.S. Pat. No. 4,057,439, issued to Lindmayer.
An alternative type of renewable energy is a solar thermal heat exchanger, which utilizes the energy of sunlight to heat a liquid, thereby providing thermal energy for heating or cooling. In this type of energy harnessing, typically a flat plate is blackened on the front to improve absorption of solar radiation and is arranged with its blackened surface facing the sun and sloped at a suitable angle to optimize the energy collected. A series of tubes is secured to the panel, and water to be heated is circulated through these tubes to extract the heat received by the panel. The back of the panel is often insulated by a layer of insulating material such as glass wool or plastic foam.
In most cases, these panels include a frontal screen made of glass or transparent plastics material, such as transparent acrylic or PVC, which allows solar radiation to pass through the screen onto the panel and retains the heat by reducing losses caused by re-radiation or convection cooling.
The warmed water from solar panels is normally circulated through a separate tank so that the temperature may build up to a maximum value being a balance between the heat input and heat losses in the system. This water is then used as feed water for the main hot water tank, as hot water is drawn off from the system. As this water is generally only warm, except in very hot weather or when the panel is used in hot climates, it cannot be used directly as hot water, and a separate heater in the main hot water tank is necessary to heat the water to usable temperatures. It is also clear that water from the solar panel cannot be used generally for maintaining the temperature of the hot water in the main tank. An example of this type of renewable energy source can be found in U.S. Pat. No. 4,089,957, issued to Bennett.
While these types of solar energy harnessing are efficient in their own capacity, they do not provide for an economical source of both thermal and electrical energy which can be utilized throughout households of the world.